I’ve read about OLED monitors and there advantages for magic mirrors. Does this matter? I can’t tell if the monitors I’ve shortlisted will fulfill this or not.

I think the OLED monitors on market today is around 5000usd (Dell 30"), little pricey at the moment.

How should I get the exact measurements for the mirror? Should I order the monitor first, take off the bezel and then

Yupp, get the monitor first, then you know what you have to work with, unless you are trying to build a ultra slim mirror you don’t really need to disassemble the monitor, which could be a bonus if it stops working while the warranty is still good.

Everything you spec’d will work fine. As for the monitor, just about anything will work. There really isn’t a “best” monitor.

What do you want to display and where do you want to display it? Quite often builders will get a monitor that is 1/4 the size of the mirror and mount the monitor so they are displayed in the upper left or right of the actual mirror. Is this to be installed as a bathroom mirror? Do you want to stare at the weather report in front of your face while you are trying to shave?

As for the best “quality” monitor, anything you buy will work great. Figure out the size you want then look at how the thing is rated by customers and professionals. People here are from all over the world. Many in the U.S. use Craigs List to find monitors.

Don’t install pm2 until you are comfortable that all of your modules are working correctly. There is good info that can be had from starting the mirror from a terminal session.